I think you want something like this for the malt bill.
75% dark Munich
20 % Pils
4% CaraMunich II
1 % carafa for color
Decoction if you wish, or steps at 133F for 10 min, 144F for 40 min., 158 - 160F for 20. Mash out.
Water should be from Martin's NHC talk, Munich profile.
18 to 20 IBUs noble hops of your choice.
I would use either 833 (Ayinger), 835 lager X (rhymes with Kloster Andechs), or 830. Ferment at 48 to 50F. Lager at 32F for 6 weeks.
You might conclude I am going to brew one soon and have been researching, and will split it between 833 and 835. There is a recipe on Weyermann's FAQ page, that is similar, but has 8.5% CaraMunich II, and that is too much for my taste.
Hope this helps. Dunkel is a rewarding beer to brew and drink. The last one I did was 80% Dark Munich, 20 % Pils, maybe a touch of Carafa for color. That makes one more like what is served in Franconia, so a little more dry.
As with a good doppelbock, the pils is for the enzymes. You want to be sure the beer dries out. Sweet german beers suck. I think a lot of american interpretations totally strike out here.